Harvesting Vibration for Downhole Power Generation

ABSTRACT

A system that is usable with a subterranean well includes a winding, a member and a circuit. The winding is located downhole in the well, and the member moves relative to the winding in response to vibration occurring in the well to cause a signal to be generated on the winding. The circuit is coupled to the winding to respond to the signal to provide power to operate a component located downhole in the well.

BACKGROUND

The invention generally relates to harvesting vibration for downholepower generation.

A typical subterranean well includes various devices that are operatedby mechanical motion, hydraulic power or electrical power. For devicesthat are operated by electrical or hydraulic power, control lines and/orelectrical cables typically extend downhole for purposes ofcommunicating power to these tools from a power source that is locatedat the surface. A potential challenge with this arrangement is that thespace (inside the wellbore) that is available for routing variousdownhole cables and hydraulic control lines may be limited. Furthermore,the more hydraulic control lines and electrical cables that are routeddownhole, the higher probability that some part of the power deliveryinfrastructure may fail. Other risks are inherent in maintaining thereliability of any line or cable within the well's hostile chemical,mechanical or thermal environment and over the long length that may berequired between the surface power source and the downhole poweroperated device.

Thus, some subterranean wells have tools that are powered by downholepower sources. For example, a fuel cell is one such downhole powersource that may be used to generate electricity downhole. Thesubterranean well may include other types of downhole power sources,such as batteries, for example.

A typical subterranean well undergoes a significant amount of vibration(vibration on the order of Gs, for example) during the production ofwell fluid. In the past, the energy produced by this vibration has notbeen captured. However, an emerging trend in subterranean wells is theinclusion of devices to capture this vibrational energy for purposes ofconverting the energy into a suitable form for downhole power.

Thus, there is a continuing need for better ways to generate powerdownhole in a subterranean well.

SUMMARY

In an embodiment of the invention, a system that is usable with asubterranean well includes a winding, a member and a circuit. Thewinding is located downhole in the well, and the member moves relativeto the winding in response to vibration occurring in the well to cause asignal to be generated on the winding. The circuit is coupled to thewinding to respond to the signal to provide power to operate a componentlocated downhole in the well.

Advantages and other features of the invention will become apparent fromthe following description, drawing and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a well according to an embodiment ofthe invention.

FIG. 2 is a flow diagram depicting a technique to generate downholepower according to an embodiment of the invention.

FIGS. 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14 depict mechanisms toenhance the generation of downhole vibrational energy according to anembodiment of the invention.

FIG. 15 depicts a system located on a sandscreen to aid in thegeneration of downhole power according to an embodiment of theinvention.

FIG. 16A is a flow diagram depicting a technique to power wireless tagsaccording to an embodiment of the invention.

FIG. 16B depicts a system to deploy wireless tags according to anembodiment of the invention.

FIG. 17 is a schematic diagram of a wireless tag according to anembodiment of the invention.

FIG. 18A is a block diagram of a system to harness and store vibrationalenergy downhole according to an embodiment of the invention.

FIG. 18B depicts a piezoelectric material based vibration energyconverter.

FIG. 19A is a block diagram of an electromagnetic based system toharness and store vibrational energy downhole according to an embodimentof the invention.

FIG. 19B depicts an electromagnetic based vibration energy converter.

FIGS. 20A, 20B and 20C are schematic diagrams of vibrational energyharvesting mechanisms according to an embodiment of the invention.

FIG. 21 is a schematic diagram of a portion of a drilling stringaccording to an embodiment of the invention.

FIG. 22 is a schematic diagram of a subsea well according to anembodiment of the invention.

FIG. 23 is a flow diagram depicting a technique to power a downhole toolaccording to an embodiment of the invention.

FIG. 24 is a flow diagram depicting a technique to use vibration in acementing operation according to an embodiment of the invention.

FIG. 25 is a flow diagram depicting a technique to evaluate potentialblockage of a downhole pipe according to an embodiment of the invention.

FIG. 26 is a flow diagram depicting a technique to communicate with adownhole tool according to an embodiment of the invention.

FIG. 27 is a schematic diagram depicting a system in which vibrationalenergy is used to communicate with downhole tools according to anembodiment of the invention.

FIGS. 28, 29 and 30 are schematic diagrams of mechanisms to harnessvibrational energy to generate electrical power according to embodimentsof the invention.

DETAILED DESCRIPTION

Referring to FIG. 1, an embodiment 10 of a well in accordance with theinvention includes a tubular string 14 (a production string, forexample) that extends into a wellbore of the well 10. The tubular string14 may include a central passageway 29 that communicates a flow 27 froma subterranean formation zone 32 (or to a formation zone in the case ofan injection well). The zone 32 represents one out of many possiblezones of the well 10. The zone 32 may be defined (i.e., isolated fromother zones) by one or more packers 30 (one being depicted in FIG. 1).

The flow 27 is a primary source of vibrational energy downhole, and thisvibrational energy is captured by a vibrational energy harvestingmechanism 20 (of a power generation tool 18) for purposes of convertingthe vibrational energy into downhole electrical power. This electricalpower, in turn, may be used to power one or more downholepower-consuming components, such as sleeve valves, ball valves, motors,actuators, sensors, sound sources, electromagnetic signaling sources, orequipment to fire “smart bullets” into a well casing, perforating gunfiring heads, controllers, microprocessors, Micro Electrical MechanicalSensors (MEMS), telemetry systems (transmitters or receivers), etc.,depending on the particular embodiment of the invention.

In some embodiments of the invention, the string 14 includes one or morefeatures to enhance the generation of vibrational energy, referred togenerally herein as a “vibration enhancement mechanism 16.” Morespecifically, the flow 27 enters the mechanism 16 that, in someembodiments of the invention, produces a locally more turbulent flow 31that flows uphole. The creation of this more turbulent flow, in turn,amplifies the vibrational energy, thereby leading to the increasedproduction of downhole power. The vibrational harvesting mechanism 20may be located in proximity to (within ten feet, for example) to thevibration enhancing mechanism 16, in some embodiments of the invention.Various embodiments of the vibration enhancing mechanism are describedbelow.

Thus, referring to FIG. 2, in some embodiments of the invention, atechnique 40 may be used to harvest vibrational energy downhole. Morespecifically, in accordance with the technique 40, the downholevibration is enhanced (block 42) such as by the vibration enhancementmechanism 16, as further described below. Next, pursuant to thetechnique 40, the downhole vibration is converted (block 44) intodownhole power to power one or more downhole power-consuming devices.

As a more specific example, FIG. 3 depicts a cross-section of avibration enhancing mechanism 50 in accordance with an embodiment of theinvention. The device 50 may be formed from a section of the string 14having an interior wall 15 that constricts the central passageway 29 ofthe string 14. More specifically, in some embodiments of the invention,the section has a circular cross-section of varying diameter; and insome embodiments of the invention, the section forms a Venturi-type flowpath. This flow path, in turn, converts the entering flow 27 into a moreturbulent flow 31 for purposes of creating more vibration. The flow pathof the device 50 thus creates vibrational energy that is harvested bythe power generator tool 18.

Other types of vibration enhancing mechanisms may be used in otherembodiments of the invention. For example, referring to a cross-sectiondepicted in FIG. 4, in some embodiments of the invention, a cantileveredmember 56 may extend from the interior wall 15 of the string 14 into thecentral passageway 29. The member 56 introduces an obstruction in theflow path 27 to create the more turbulent flow 31.

As another example, FIG. 5 depicts a cross-sectional view of avibration-enhancing mechanism 60 that contains a flexible member 62 thathas one end that is attached to the interior wall 15 of the tubularstring 14 and another free end that extends into the central passageway29. Due to this arrangement, the flexible member 62 moves in response tothe flow 27 to create the more turbulent flow 31 and thus, enhance thegeneration of vibrational energy.

As another example, FIG. 6 depicts a cross-sectional view of avibration-enhancing mechanism 66 that, similar to the Venturi-typeflowpath of the mechanism 50 (FIG. 3), includes a restricted flow path68 for purposes of increasing vibration downhole. In some embodiments ofthe invention, the flow path 68 has a circular cross-section sectionthat varies in diameter.

It has been discovered that a production string (a possible embodimentof the tubing string 14 (FIG. 1)) has a fundamental vibration mode inwhich the cross-section of the production string expands and contractsin two orthogonal cross-sectional directions. For example, as depictedin a cross-section of a production tubing section in FIG. 7, during theflow of fluid through a production tubing string, the string may includea cross-section that expands in the positive and negative Y directionswhile the cross-section of the production tubing contracts in thepositive and negative X directions. Next, pursuant to the fundamentalvibration mode, the cross-section of the production tubing expands inthe positive and negative X directions and contracts in the positive andnegative Y directions. This process repeats to establish the fundamentalvibration mode.

As depicted in FIG. 7, in some embodiments of the invention, thethickness of the wall of the production string 70 may be radially variedto select the axis and otherwise enhance the fundamental vibration mode.More specifically, the cross-section of the string may include thinnerportions 72 that extend along the X-axis and thinner portions 74 thatextend along the Y-axis. The remaining portions 76 of the cross-sectionare thicker. Thus, due to this arrangement, the flexing of theproduction string 70 in the above-described cross-sectional directionsis enhanced due to the thinning of the production tubing stringcross-section in orthogonal directions. Increasing the flexing of theproduction tubing string, in turn, enhances the vibrational energy thatis generated by the flow of fluids through the production tubing string.Thus, the arrangement that is depicted in FIG. 7 enhances thevibrational energy that is converted into electrical energy downhole.

As another example of a mechanism to enhance vibrational energydownhole, FIG. 8 depicts a mechanism 80 that includes a spring 81 thatmay be attached to, for example, the interior wall 15 of the string 14and extend into the central passageway 29. In yet another embodiment ofthe invention, a vibration enhancing mechanism 84 (a cross-section ofwhich is depicted in FIG. 9) includes a wedge-shaped flow diverter 86that is inserted into the flow path 27 for purposes of creating a moreturbulent flow. As depicted in FIG. 9, regions 88 exist between thediverter 86 and the wall of the string 14 for purposes of allowing fluidto pass therethrough. However, the flow diverter 86 introducesadditional turbulence into the flow 27, thereby creating additionalvibration downhole.

In some embodiments of the invention, a piece of downhole equipment thatmay already be located downhole may be strategically placed near thepower generation tool 20 (FIG. 1) for purposes of enhancing vibrationnear the tool 20. For example, referring to FIG. 10, a multiphase mixer86 may be placed in close proximity (within ten feet for example) to thepower generation tool 20. The multiphase mixer 86, as its name implies,typically is used in production to blend various phases of well fluidtogether. The mixer 86 may include, for example, an opening 102 thatreceives the flow 27. The mixer 86 may also include an internal chamber99 that includes various orifices 100 through which the flow may proceedto flow upstream and produce the flow 31 through the central passageway29.

In other embodiments of the invention, a vibrational energy-enhancingmechanism 108 (a cross-section of which is depicted in FIG. 11) may beused. The mechanism 108 includes a blind T 112 that is inserted into theflow path 27. The blind T 112 is surrounded by openings 110 that permitthe flow of the fluid around the blind T 112. However, the inclusion ofthe blind T 112 in the flow path 27 creates turbulence that, in turn,enhances the vibrational energy downhole.

Referring to FIG. 12, in some embodiments of the invention, avibration-enhancing section 120 of the string 15 may include a spiral orhelical groove 124 that extends along the inner surface of the wall 15of the string 14. As depicted in FIG. 12, the longitudinal axis of thegroove 124 is concentric with the longitudinal axis of the string 14.

In some embodiments of the invention, a free flowing part may be used toenhance the generation of vibrational energy downhole. For example, avibration enhancing mechanism 130 (a cross-section of which is depictedin FIG. 13) may include a chamber 132 (in the flow path 27) thatcontains a ball 140. Analogous to a policeman's or an umpire's whistle,the ball 140 is trapped inside the chamber 132, in that lower 139 andupper 135 openings in the chamber 132 are sized to permit fluid (but notthe ball 140) to pass into and out of the chamber 132 and contact theball 140. The interaction of the fluid with the ball 140 createsvibrational energy that may be harvested for electrical power.

In some embodiments of the invention, an electrical device that consumesharvested power downhole may also be used to generate vibrational energyused for purposes of power generation. For example, as depicted in FIG.14, in some embodiments of the invention, a vibration-enhanced mechanism150 may include an electrical pump 152 (a beam-type pump, a rod-typepump or an electrical submersible pump (ESP)), as just a few examples.The electrical pump 152 receives the flow 27 to produce the output flow31. The operation of and fluid flow through the pump 152 enhances thevibrational energy.

Although the vibration-enhancing mechanisms and power generatingmechanisms (such as the power generator tool 18) that are describedabove are generally located in the central passageway of the string 14,it is noted that in other embodiments of the invention, these mechanismsmay be located in other regions of the well. For example, in someembodiments of the invention, these mechanisms may be located on theoutside of the string 14 or located in a side packet mandrel, as furtherdescribed below in connection with FIG. 22.

As a more specific example, referring to FIG. 15, in some embodiments ofthe invention, a vibration-enhancing mechanism 160 may be located on theoutside of a sandscreen 158. Thus, the mechanism 160, which may be anyof the above-described mechanisms, may be located in a flow path locatedbetween the exterior and the interior of the sandscreen 158. In someembodiments of the invention, the mechanism 160 may be located insidethe sandscreen 158. Furthermore, in some embodiments of the invention, apower generator (not shown) to generate electrical power fromvibrational energy may be mounted to the sandscreen 158 and may belocated either on the outside or inside of the sandscreen 158.

Although in the embodiments described above, the power generationmechanism 20 is depicted (FIG. 1) as being attached to the string 14, inother embodiments of the invention, the power generation mechanism 20may not be fixed in position relative to the string 14. For example, insome embodiments of the invention, a wireless (a radio frequency (RF),for example) tag may be used to measure various properties in asubterranean well. These properties may include, for example, detectionof water or chemical constituents, such as hazardous H2S, or measurementof pressure and temperatures at various positions in the well. The tagmay be free-flowing, in that the tag may be released into the well andtake a measurement at a particular depth in the well. Many variationsare possible. For example, the tag may be activated at a particulardepth, a particular temperature, a particular pressure, etc.

For purposes of supplying power to the tag, the tag may derive its powerfrom the vibrational forces that are experienced by the tag itself.Thus, instead of being attached to a static structure, such as thestring 14, for example, the tag is free-flowing and is imparted withvibrational energy as the tag flows in the well. This vibrationalenergy, is converted by a vibrational energy transformer of the tag intoelectrical power for the tag.

Thus, referring to FIG. 16A, in some embodiments of the invention, atechnique 180 includes deploying (block 182) wireless tags in asubterranean well. Vibrational energy is used (block 184) to activate(i.e., power up and continue providing power to) the tags. Onceactivated, measurements are then performed (block 186) with the tags.

FIG. 16B depicts a subterranean well 200 in accordance with thetechnique 180. As shown in FIG. 16B, the well 200 may include a tubularstring 204 (a production tubing, for example) into which several tags220 have been placed into the central passageway of the well 200. As anexample, the well 200 may include a surface pump 206 that may controlthe flow of fluid through the well 200. For example, the pump 206 mayhalt fluid flow through the string 204 to allow the tags 220 to descendinto the well 200. When the tags have collected the data, the pump 206may then be re-activated to cause fluid to flow uphole and thus returnthe tags 220 toward the surface.

In some embodiments of the invention, the well 200 may include a tagreader 230 to extract information from the tags 220 as the tags 220return from downhole. As the tags 220 descend downhole, vibrationalenergy imparted on the tags 220 generate power on the tag 220 toactivate the tag 220 so that the tag 220 may then take the appropriatemeasurement downhole.

Referring to FIG. 17, in some embodiments of the invention, the tag 220may have an architecture that is generally depicted in FIG. 17. Thisarchitecture may include, for example, a processor 248 that is coupledto a sensor 250 (a pressure or temperature sensor, for example) througha bus 248. The processor 248 may execute instructions that are stored ina memory 244 (also coupled to the bus 249) as well as store data fromthe sensor 250 in the memory 246. The architecture may include variousother features, such as a transmitter to transmit to the reader 230(FIG. 16B), depending on the particular embodiment of the invention.

As depicted in FIG. 17, the tag 220 includes power generation circuitrythat includes, for example, a vibrational energy converter 240. As itsname implies, the converter 240 produces a voltage (for example) inresponse to vibrational energy that occurs to the tag 220. A DC-to-DCconverter 242 converts this voltage into a regulated voltage thatappears on voltage supply lines 246. The voltage supply lines 246, inturn, furnish power to the various components of the tag 220, such asthe sensor 250, processor 248 and memory 246, as just a few examples.

In some embodiments of the invention, the tag 220 may include a reserveenergy source, such as a battery 244, that is coupled to the outputterminals of the DC-to-DC converter 242. The battery 244 serves as anenergy buffer to store excess energy that is provided by the converter240 so that this energy may be used to regulate the power that isprovided to the power-consuming components of the tag 220.

In some embodiments of the invention, the power harvesting circuitry(whether on a wireless tag or affixed to the string 14) may have anarchitecture 260 that is generally depicted in FIG. 18A. Thisarchitecture 260 includes a vibration responsive strain inducer 264. Asexamples, the vibration responsive strain inducer 264 produces amechanical force that, as its name implies, imparts a physical strain ona piezoelectric material 262. A piezoelectric material, by its verynature, produces a terminal voltage responsive to the strain that isinduced on the material. Therefore, in response to the strain producedby the inducer 264, the piezoelectric material 262 produces a voltagethat appears on a signal line 266. This voltage, in turn, is regulatedto a specific DC level by a DC-to-DC converter 268 to produce aregulated voltage that appears on a power supply 270.

Thus, the inducer 264, piezoelectric material 262 and converter 268 forma basic power-harvesting generator 273 in accordance with an embodimentof the invention.

Although depicted in FIG. 18A as producing DC power, it is noted that inother embodiments of the invention, the generator 273 may include aninverter for purposes of generating an AC voltage. Thus, otherembodiments are within the scope of the following claims.

Additionally, in some embodiments of the invention, a particular wellmay include several generators 273 that are connected in parallel to thevoltage supply 270. Furthermore, in some embodiments of the invention, abattery 272 may be coupled to the voltage supply line 272 for purposesof serving as an energy buffer to absorb and supply power, depending onthe particular vibrational energy being experienced at the time.

In accordance with an embodiment of the invention, the vibrationresponsive strain inducer 264 and piezoelectric material 262 may, insome embodiments of the invention, have a form 280 that is depicted inFIG. 18B. More specifically, the arrangement 280 may include apiezoelectric material 282 that is located between fairly rigid members286 and 284. These members may be formed from, as examples, part ofhousing of the string 14 as well as explicit plates. A cantilevered mass290 is connected to the plates 284 and 286 to exert a strain force onthe piezoelectric material 282 in response to the vibrational energysensed by the mass 290. Thus, vibrational energy causes movement of themass 290, and this movement, in turn, induces stress to cause thepiezoelectric material to generate a corresponding voltage.

Referring both to FIGS. 19A and 19B, in some embodiments of theinvention, the power harvesting circuitry (whether on a wireless tag oraffixed to the string 14) may have an architecture 260 that is generallydepicted in FIG. 19A. This architecture 260 includes a vibrationresponsive strain inducer 264. As examples, the vibration responsivestrain inducer 264 produces a mechanical force that, as its nameimplies, imparts a physical strain on an electromechanical energyconversion, or generator, that is depicted, as an example, in FIG. 19B.An electromagnetic energy converter, by its very nature, produces aterminal voltage induced by an electrical conductor, or coil, moving ina magnetic field that is maintained by a suitable ferro-magneticmaterial, permanent magnet. Therefore, in response to the strain ormotion produced by the inducer 264, the electromagnetic converterproduces a voltage that appears on a signal line 266. This voltage, inturn, is regulated to a specific DC level by a DC-to-DC converter 268 toproduce a regulated voltage that appears on a power supply 270.

In the various embodiments of the invention, the mass that induces thestrain on the piezoelectric material may not be a cantilevered mass butalternatively, may be another type of strain inducer that generates astrain on the piezoelectric material in response to vibrational energy.For example, in some embodiments of the invention, the wall of thetubular string 14 (see FIG. 1) may be lined with a piezoelectric coating304, as depicted in FIG. 20A. More specifically, the piezoelectricmaterial lining 304 may completely or partially coat the interior wallof the tubular string 14, according to the particular embodiment of theinvention. Due to the above-described fundamental mode of vibration ofthe tubular string 14, this vibration induces a strain on thepiezoelectric material coating 304 to generate a corresponding voltageacross the material 304.

Although not depicted in FIG. 20A, in some embodiments of the invention,a thin insulation layer may be interposed between the lining 304 and theinterior surface of the tubing string wall for purposes of isolating theterminal voltage appearing on the coating 304 from the tubing string 14.

As another example of a strain-inducing mechanism in accordance with theinvention, FIG. 20B depicts a mechanism 304 that includes a flexibleflow member 62 (see FIG. 5) that has a piezoelectric electric coating308 lining the flexible member 62. Thus, the motion of the flexiblemember 62 induces a strain on the material 308 to generate a voltage onthe material 308.

Thus, as can be seen, the piezoelectric coating may be applied tovarious downhole components that are subject to vibration, in that thevibration induces a strain on the piezoelectric coating, and this straininduces a voltage that may be converted into downhole power. As yetanother example, FIG. 20C depicts the blind T 112 (see FIG. 11) that isat least partially covered by a piezoelectric coating 311. Thus, othervariations are possible and are within the scope of the appended claims.

Due to the generation of electrical power downhole, various controllines and electrical cables do not need to be extended from the surfaceof the well. Furthermore, generating electrical power downhole may beadvantageous for purposes of reducing cabling between downholecomponents. For example, FIG. 21 depicts a drill string 320 thatincludes a mud motor 324 and a drill bit 328. The drill string 320 mayinclude sensors 326 that are used for purposes of monitoring operationof the drill string 320 and monitoring general operation of thedrilling. The sensors 326 typically are located close to the drill bit328. A particular challenge with this arrangement is that the sensors326 may be located away from a power source and thus, electrical cablesmay have to span across the mud motor 324 for purposes of deliveringpower to the sensors 326. However, in accordance with embodiments of theinvention, the sensors 326 may be in close proximity to power generationcircuitry 324 that generates electrical power from the vibration of thedrill string 320, such as the vibration that occurs during operation ofthe mud motor 324. Due to this arrangement, cabling does not have to beextended across the mud motor 324 for purposes of delivering power tothe sensors 326.

Referring back to FIG. 1, as another example of the reduction of cablingdue to the generation of power downhole, the well 10 may include anintelligent completion, a completion that contains circuitry thatautomatically controls downhole equipment independently from anycommands that are communicated from the surface of the well. Forexample, the string 14 may be a production string and include a valve 21(a sleeve valve or ball valve, as examples) that is electricallyoperated by power that is produced by the power generator tool 18. Anintelligent controller 23 of the string 14 may, for example, use asensor 111 (also of the string 14) to detect one or morecharacteristic(s) of the flow 27. The sensor 111 may include one or moreof a pressure sensor, a temperature sensor, a fluid composition sensorand a Micro Electrical Mechanical Sensor (MEMS), depending on theparticular embodiment of the invention.

Based on the detected characteristic(s), the controller 23 operates avalve 21 (a sleeve valve or ball valve, as examples) to control the flow27. For example, the controller 23 may determine the flow 27 has a highwater content level and close the valve 21 to shut off flow from thezone 32. As another example, the controller 23 may also control thevalve 21 to regulate a pressure in the well. The controller 23, sensor11 and valve 21, in some embodiments of the invention, receive powerfrom the power generator tool 18. In some embodiment of the invention,the controller 23, sensor 111 and valve 21 receive all of theiroperating power from the power generating tool 18.

As another example of a power consuming device that may rely on energyderived from vibrational energy downhole, FIG. 22 depicts a subsea well400 that extends beneath a sea floor 402. The subsea well 400 includes asubsea well tree and wellhead 404; and a tubular string 406 that extendsinto a wellbore of the well. A robot 414 may be located inside thetubular string 406. The robot 414 may generally be autonomous in thatthe robot 414 does not rely on a tethered connection for purposes ofoperating in the subsea well to perform an intervention, for example.Thus, for purposes of generating power, robot 414 may dock to powerconnectors that are electrically coupled to a power generation mechanism410 that generates downhole electrical power from vibrational energy.

As an example, the power generation mechanism 410 may be located in aside pocket mandrel 412 that is formed in the tubing 406. As shown inFIG. 2, due to the inclusion of the power generating mechanism 410 andthe side pocket mandrel 412, the central passageway of the tubing string406 is unobstructed for purposes of operating the robot 410, performingan intervention with other tools, producing well fluid, etc.

The subsea well 400 may include other components that are powered by thepower generating mechanism 410, such as, for example, telemetrycircuitry 420 that is located on the sea floor 402 and is used tocommunicate (via acoustic, optical or electromagnetic communication, asexamples) with a surface platform (not shown in FIG. 22). The powergenerating mechanism 410 may also deliver power (via communication lines425) to electrical storage 424 (a battery, for example) that is locatedon the sea floor 402.

The above-described arrangements rely on the vibrational forces that areproduced either by downhole equipment or by the flow of well fluid incontact with a particular vibration-enhancing mechanism. However, insome embodiments of the invention, vibrations may be intentionallyintroduced into a fluid or slurry that is introduced downhole from thesurface.

For example, FIG. 23 depicts an embodiment of a technique 430 inaccordance with the invention, which uses vibrations in a gravel packflow for purposes of communicating vibrational energy downhole that maybe used to produce downhole power. More specifically, in accordance withthe technique 430, vibrations are induced in a gravel packed flow, asdepicted in block 432. For example, these vibrations may be induced bypressure pulses that are applied to a slurry flow as well as lessregulated vibrational energy that is applied to the flow. Regardless ofthe specific form of the vibrational energy, the vibrational energy isapplied at the surface of the well and is communicated downhole via theflow. Pursuant to the technique 430, this vibrational energy is used(block 434) to generate downhole power, such as for a downhole tool tobe used during or after the completion of gravel packing (for example).

Referring to FIG. 24, other types of downhole flows may be used forpurposes of communicating vibrational energy downhole. For example, FIG.24 depicts a technique 444 for purposes of communicating vibrationalenergy via a cement flow. Pursuant to the technique 444, a vibration isintroduced in the cement flow, as depicted in block 446. Similar to thegravel packed flow discussed in connection with FIG. 23, vibrationalenergy may be imparted to the cement flow by, for example, pulses orother types of vibrational energy. This vibrational energy is then usedto generate power downhole (as depicted in block 450) for one or moredownhole tools.

Not only may the vibrational energy be used to produce downhole power,other uses of the vibrational energy may be used, in accordance withparticular embodiments of the invention. For example, FIG. 25 depicts atechnique 470 for purposes of using vibrational energy to detectproblems with tubular passageways (production tubing passageways, gravelpacking shunt tubes, etc.) downhole. In this manner, pursuant to thetechnique 470, vibrational energy is detected (block 472) downhole andthen used to evaluate (block 474) possible blockage in response to thedetected energy. The vibrational energy may be generated downhole (inresponse to a fluid flow, for example) and/or may be communicateddownhole by a flow (a cement or gravel packing flow, as examples) fromthe surface of the well. As a more specific example, in some embodimentsof the invention, a circuit may analyze the spectral components of theproduced vibrational energy and based on comparing the computed spectralenergy to reference patterns, may determine whether or not a blockageexists in a particular downhole member.

As yet another example of the use of vibrational energy to perform afunction other than solely being converted into downhole power, atechnique 481, depicted in FIG. 26, uses vibrational energy for purposesof communicating with the downhole tool. More specifically, pursuant tothe technique 481, vibrational energy is detected (block 482) downhole,and this detection is used (block 484) to handshake, that is tocommunicate commands and/or measurements with a specific downhole tool.

As a more specific example, FIG. 27 depicts a well 500 in accordancewith the invention that includes a tubular string 582 that extends intoa wellbore of the well 500. The string 582 includes gas lift valves 584that may be used for purposes of injecting gas for purposes of liftingproduction fluid uphole. A circuit 590 on the surface of the well 500monitors vibrational energy that is generated by the gas lift valves 584for purposes of determining when a particular gas lift valve 584 hasbeen activated. In this regard, in some embodiments of the invention,each gas lift valve 584 may be designed to have a unique andidentifiable resonant frequency when activated. This vibrationalfrequency, in turn, is detected by the circuit 590 for purposes ofidentifying when the gas lift valve 584 has activated.

Alternatively, in some embodiments of the invention, each gas lift valve584 may be designed to release tags that contain a unique andidentifiable code that can be communicated to a suitable circuit at thesurface located as 590 in FIG. 27.

Other embodiments are within the scope of the following claims. Forexample, many other techniques may be used to generate electric powerfrom vibrational energy downhole. For example, in some embodiments ofthe invention, a capacitor may be used that has at least one plate thatis mounted to a spring. A voltage may be stored on the capacitor so thatby variation of the distance between the plates of the capacitor, avarying voltage is produced. This varying voltage, in turn, may beconverted into power for a particular downhole tool.

As another example of a mechanism to generate power from downholevibrational energy, FIG. 28 depicts, as a variation on theelectromagnetic energy converter depicted in FIG. 19B a mechanism 600that includes a coil 602 that generally circumscribes amagnetically-charged ferrous material 610. The material 610, in turn,may be mounted on springs 606 to move longitudinally along the axis ofthe coil 602, as depicted in FIG. 28. This movement of the material 610,in turn, produces a voltage on the coil 602 and this voltage may beconverted into downhole power. In some embodiments of the invention, thecoil 602 may be embedded in a mandrel 604 that generally circumscribesthe ferrous material 610.

In another variation, FIG. 29 depicts a power generation mechanism 620in which the mandrel 604 (that contains the coil 602) moves instead ofthe ferrous material 610. More specifically, the ferrous material 610may be relatively stationary; and the mandrel 604 is mounted on springs624. Thus, vibration causes movement of the mandrel 604 (and coil 602)with respect to the ferrous material 610. This movement, in turn,induces a voltage on the coil 602, and this voltage may be used togenerate power downhole. It is noted that many other variations arepossible in the various embodiments of the invention. For example, FIG.30 depicts a mechanism 650 similar to the mechanism 600 except that theferrous material 610 is mounted via springs 651 so that the ferrousmaterial 610 moves laterally with respect to the coil 602. This lateralmovement, in turn, changes the magnetic permeability of the path insidethe coil 602 to change the voltage that appear on the coil's terminals.As depicted in FIG. 30, in some embodiments of the invention, the spring651 may couple the ferrous material 610 to the inner side-walls of themandrel 604.

Other variations are possible. For example, in other embodiments of theinvention, the ferrous material 610 may be distributed on a dynamo thatrotates inside the coil 602 to generate voltage on the coil's terminals.The rotational speed of the dynamo increases with the level of vibrationin the well.

While the present invention has been described with respect to a limitednumber of embodiments, those skilled in the art, having the benefit ofthis disclosure, will appreciate numerous modifications and variationstherefrom. It is intended that the appended claims cover all suchmodifications and variations as fall within the true spirit and scope ofthis present invention.

1. A system usable with a subterranean well, comprising: a windinglocated downhole in the well; a member to move relative to the windingin response to vibration occurring in the well to cause a signal to begenerated on the winding; and a circuit coupled to the winding torespond to the signal to provide power to operate a component locateddownhole in the well.
 2. The system of claim 1, wherein the membercomprises a magnetic material.
 3. The system of claim 1, wherein thewinding is attached to a tubular string extending into the well, and thecoil moves relative to the string.
 4. The system of claim 1, wherein thecoil is attached to a tubular string extending into the well, and thewinding moves relative to the string.
 5. The system of claim 1, whereinthe relative motion occurs along a direction generally traverse to alongitudinal axis of a tubular string that extends into the well.
 6. Thesystem of claim 1, wherein the relative motion occurs along a directiongenerally aligned with a longitudinal axis of a tubular string thatextends into the well.
 7. The system of claim 1, wherein the circuitcomprises a voltage regulator to generate a regulated voltage to powerthe component in response to the signal.
 8. A system usable with asubterranean well, comprising: a tubular string comprising a centralpassageway and a flow diverter located in the central passageway toenhance vibrational energy in the tubular string in response to a flowcontacting the flow diverter; and a power generator located downhole inproximity to the flow diverter to respond to the vibrational energy togenerate power for a downhole component.
 9. The system of claim 8,wherein the flow diverter comprises a wedge-shaped member.
 10. Thesystem of claim 8, wherein the flow diverter comprises a blind T. 11.The system of claim 8, wherein the flow diverter comprises acantilevered member extending from an interior sidewall of the tubularmember.
 12. The system of claim 8, wherein the flow diverter is locatedwithin approximately ten feet of the power generator.
 13. A systemusable with a subterranean well, comprising: a tubular string comprisinga central passageway having a varying cross-section to enhancevibrational energy in the tubular string in response to a flow throughthe cross-section; and a power generator located downhole in proximityto the varying cross-section to respond to the vibrational energy togenerate power for a downhole component.
 14. The system of claim 13,wherein the varying cross-section maintains an approximate circularshape.
 15. The system of claim 13, wherein the varying cross-sectioncomprises a Venturi-type cross-section.
 16. The system of claim 13,wherein the varying cross-section is located within approximately tenfeet of the power generator.
 17. A system usable with a subterraneanwell, comprising: a chamber located downhole in the well, the chambercomprising at least one opening to receive an inlet fluid flow and atleast one opening to provide an outlet fluid flow; an untethered memberto move freely in the chamber in response to the inlet fluid flow togenerate vibrational energy; and a power generator located downhole inproximity to the chamber to respond to the vibrational energy togenerate power for a downhole component.
 18. The system of claim 17,wherein the untethered member comprises a ball.
 19. The system of claim17, wherein the untethered member is located within approximately tenfeet of the power generator.
 20. A system usable with a subterraneanwell, comprising: a tubular string extending into the well, the stringcomprising a passageway to receive a fluid flow; a flexible membercomprising a first end attached to the tubular string and a second freeend located in the passageway to generate vibrational energy; and apower generator separate from the flexible member and located downholein proximity to the flexible member to respond to the vibrational energyto generate power for a downhole component.
 21. The system of claim 20,wherein the flexible member comprises a spring.
 22. The system of claim20, wherein the spring is located within approximately ten feet of thepower generator.
 23. A system usable with a subterranean well,comprising: a downhole component located in the subterranean well toreceive power and perform a downhole function in response to thereceived power; and a power generator located downhole in proximity tothe downhole component to respond to vibrational energy from thedownhole component to generate the power received by the downholecomponent.
 24. The system of claim 23, wherein the downhole componentcomprises at least one of an electrical submersible pump, a rod-typepump and a beam-type pump.
 25. The system of claim 23, wherein thedownhole component is located within approximately ten feet of the powergenerator.
 26. A system usable with a subterranean well, comprising: atubular string extending into the well, the tubular string comprising awall defining a passageway through the string and having a varyingthickness to amplify a fundamental mode of vibration of the tubularstring; and a power generator located downhole and coupled to thetubular string to respond to vibrational energy from the tubular stringto generate power for a downhole component.
 27. The system of claim 26,wherein the wall comprises thinner regions separated from each other byapproximately ninety degrees about a longitudinal axis of the tubularstring.
 28. A system usable with a subterranean well, comprising: amultiphase fluid mixer located in the subterranean well; and a powergenerator located downhole in proximity to the mixer to respond tovibrational energy from the mixer to generate power for a downholecomponent.
 29. The system of claim 28, wherein the downhole component islocated within approximately ten feet of the power generator.
 30. Asystem usable with a subterranean well, comprising: a tubular memberlocated downhole in the subterranean well, the tubular member comprisinga wall defining a passageway to receive a fluid flow and a groove formedin the wall to enhance vibrational energy produced by the fluid flow;and a power generator located downhole in proximity to the groove torespond to vibrational energy from the mixer to generate power for adownhole component.
 31. The system of claim 30, wherein the groovecomprises a spiral groove formed along a longitudinal axis of thepassageway.
 32. The system of claim 30, wherein the groove is formed onan interior surface of the wall.
 33. A system usable with a subterraneanwell, comprising: a sandscreen; and a power generator mounted to thesandscreen to respond to vibrational energy from the sandscreen togenerate power for a downhole component.
 34. The system of claim 33,wherein the power generator is mounted to an exterior of the sandscreen.35. A system usable with a subterranean well, comprising: a tubularmember comprises a side pocket eccentric to a central passageway of thetubular member; and a power generator located in the side pocket torespond to vibrational energy to generate power for a downholecomponent.
 36. A method usable with a subterranean well, comprising:deploying wireless tags in the well to measure properties of the well asthe tags flow through the well; and using vibrational energy transferredto the tags during the flowing through the well to activate the tags.37. The method of claim 36, further comprising: for each tag, deployingthe tag in an unpowered state into the well and converting vibrationalenergy transferred to the tag during the flowing into electrical powerto power circuitry of the tag.
 38. The method of claim 36, wherein atleast one of the tags measures at least one of a pressure and atemperature in the well.
 39. A system usable with a subterranean well,comprising: a plurality of generators located downhole in the well, eachof the generators independently generating power in response tovibrational energy, wherein the generators are electrically coupledtogether to each contribute to a stored energy.
 40. The system of claim39, wherein output terminals of the generators are coupled in parallel.41. The system of claim 39, further comprising: a battery, wherein thegenerators are each adapted to store energy in the battery.
 42. A methodusable with a subterranean well, comprising: initiating a flow from asurface of the well; and using vibrational energy from the flow to powera downhole component.
 43. The method of claim 42, further comprising:adding vibrational energy at the surface to increase power productiondownhole.
 44. The method of claim 43, wherein the adding comprises:pulsing the flow.
 45. The method of claim 42, wherein the flow comprisesa gravel slurry used in a gravel packing operation.
 46. The method ofclaim 42, wherein the flow comprises a cement flow used in a cementingoperation.
 47. A method usable with a subterranean well, comprising:detecting vibrational energy downhole in the well; and using thedetected vibrational energy to evaluate possible blockage in a downholetubular member.
 48. The method of claim 47, further comprising: usingthe vibrational energy to generate power for a downhole component.
 49. Amethod usable with a subterranean well, comprising: detectingvibrational energy generated downhole; identifying one of a plurality ofdownhole tools capable of generating the vibrational energy; using theidentification to acknowledge operation of said identified tool.
 50. Themethod of claim 49, further comprising: constructing each of thedownhole tools to have a different vibrational frequency duringoperation.
 51. The method of claim 49, wherein the downhole toolscomprise gas lift valves.
 52. A system usable with a subterranean well,comprising: a downhole component; and a controller to operate thecomponent independently from a command from the surface of the well inresponse to a sensed characteristic downhole, wherein at least one ofthe downhole component and controller receive power generated downholefrom vibrational energy.
 53. A system usable with a subterranean well,comprising: a drilling string comprising a drill bit and a motor tooperate the drill bit; and a sensor to sense a drilling characteristic,wherein the motor is located between the sensor and the motor, andsensor is powered by electrical power generated from vibrational energydownhole.
 54. The system of claim 53, wherein the sensor does notreceive power from any power cable extending across the motor.